// 将下面异步代码使用 Promise 的方式改进

setTimeout(function () {
  var a = "hello";

  setTimeout(function () {
    var b = "lagou";

    setTimeout(function () {
      var c = "I ❤️ U";
      console.log(a + b + c);
    }, 10);
  }, 10);
}, 10);

Promise.resolve()
  .then(() => "hello")
  .then((res) => res + "lagou")
  .then((res) => res + "I ❤️ U")
  .then((res) => console.log(res));
